Process of and apparatus for steam distillation



Nov 11, 193Q. E.- H. LESLIE ET AL 77 PROCESS OF AND APPARATUS FOR STEAMDISTILLATION Filed May 11, 1923 pemtow 3.51 abtomaa J I Patented Nov.11, 1930 UNITED STATES PATENT OFFICE EUGENE H. LESLIE AND EDWIN m.BAKER, E ANN ARBOR, MICHIGAN PROCESS OF AND APPARATUS. FOR STEAMDISTILLATION Application filed May 11, 1923. Serial No. 638,175.

vision of a process of and an apparatus for the steam distillation ofsolutions or mixtures, and the accomplishment of this object in a moreeificient and economical manner than has heretofore been possible.

such a process to the distillation of petroleum oils or distillates andto recover various ffactions therefrom.

In the present application there are described an apparatus and aprocess that are in many respects similar to the apparatus and processdescribed in our co-pending application, Serial No. 626,274, filed Mar.20, 1923; and specific reference 'is made to said application for adescription of the general manner in which liquids and vapors aretreated, and for the general theory of operation.

Reference is also made to our co ending application, Serial No. 626,273, filed J. ar. 20, '1923, fora description of the operation of thevaporizer disclosed therein, which is in many respects similar to thevaporizer emtion.

The preferred embodiment of the present ging 2; andsaid fractionator isprovided at the top with a vapor exit 3 leading to a re- .flux condenser4, which may be operated I the vapors. away the uncondensed gases to asuitable absorber, and a reflux pipe 6 joins the bottom of the condenserto the top of the fractionator. The pipe6 serves to convey-the A,further object of the invention is'to apply ployed in the practice ofthe present invention; the figure of the drawing shows an ap-'- eitheras a partial or a total condenser or A pipe 5 is provided to leadcondensed liquid to the top of the fractionator. A conduit 7 'having anumber of conduits 8 branching therefrom to' the various sections of thefractionator, serves to conduct the hot liquid to the fractionator to befractionated. Branch conduits8 are preferably provided for each sectionand a valve is placed in each conduit, so that the hot liquid may beconducted to any desired section of the fractionator, or to two or moresections 6 simultaneously. The fractionator is provided with any desirednumber of sections and the sections are provided with nipples 9 in orderto permit liquid to descend from one section to the other, topermitvapors to ascend, and to cause liquid to accumulate onthe platesof the sections. Means are provided to withdraw this liquid from anysection as desired; said means comprising a number of pipes'10, providedwith valves and connected to the sections as shown and leading tosuitable receivers. A suitable packing material 11 is placed within thesections for the purpose of providing a very large sur- 1 face ofcontact for the vapors and liquids, and this packing material mayadvantageously consist of ring or jackstone packings. Pro

vision may also be made for the removal of gases by suitably connectedipes.

, At the bottom of the fractlonator is shown 8 a pipe or conduit 12 thatconnects the fractionator to a vaporizer 13, which is operated tovaporize part of the liquid residue coming down the sections of thefractionator and passing through the conduit 12 into the vaporizer, Apipe-still 14'is connected to the vaporizer by means of pipes 15 and 16,the former serving to conduct the liquid reslduum in the vaporizer tothe still, and the latter serving to return it thereto-in a heatedconditiqn. The ipe 16 may be provided with a pressure re ucing valve 17,and the pipe 15 has positioned 'in its circuit a pum 18 which operatesto circulate the liqui The liquid delivered to the vaporizer strikes abafile'19 from which the liquid spreads over a tower packing 20 andthence trickles downwardly through the' packing zone. A second packing21 is provided above the f packing 20. A liquid exit 22 is connected topose o the bottom of the vaporizer, and it is provided with a valve 23operated by a suitable mechanism 24 that is controlled by a float 25arranged as shown.

An open steam coil 26 is positioned in the lower portion of thevaporizer for the purinjecting steam into the liquid which collectstherein.

The method of operation is as follows:

The oil, distillate, oriother liquid or mixture is pumped throughsuitable heat exchange devices iniwhich heat available in the residuumfrom the vaporizer, or from other source, is in part transferred to theincoming liquid. The latter then enters the manifold "or conduit 7 andis introduced into any previously selected section of the fractionato'r.The choice of the section into which the liquid is introduced depends onthe nature and purpose of the distillation. If it is desired that theresiduum from the still is to be free from the more volatil componentsof the liquid, but the distillate not entirely free from the lessvolatil components, the feed would be introduced into one of theuppersections of the fractionator. If it" is desired that the distillatecontain only the volatil components of the liquid and that the residuum;-need not be necessarily entirely free from the volatilcom onents, thenthe feed. would be introduce into. one of the lower sections of thefractionator. If both residuum and distillate mustbe sharply cut, thefeed would be introduced into one of the sections near the middle of thefractionator. It will be evident that'the proper location of the feedsection is in any case easily determined by trial.

In thefractionator, the process of change of composition ofdescendingliquid and ascending vapor is similar to that described'in ourco-pendingapplication, 'Serial No. 626,274, but it diifers in'thisrespect, that two liquids mix and descend that portion of the'fractionator below the feed section, these liq-- uids being the feedliquid and the liquid run.-

ning down the column from the reflux condenser at the top thereof.Otherwise the changes and operations going on within the 'fractionatorare substantially similar to those taking placein the fractionator ofthe above mentioned application.

The liquid flows from the bottom of the "fractionator through theconduit 12 into the vaporizer 13 where'it collects and is Withdrawnthrough the pipe 15 by means of the pump 18, and forced through theheater coils of the pipe-still 14, the pipe 16, and the valve 17. Upondischarge upon the distributing bathe-plate 19 it is spread over thesurfaces of the packing 20, whereupon a portion of the liquid isvaporized. This vapor together with any that may have been formed inthe" heating-coils of the still, ascends through the packing 21. Duringits passage throughthe .moved as the result of impingement on thesurfaces of. the packing. The unvaporized liquid from the packing 20together with downwardly flowing liquid from the fractionator collectsin the bottom of the vaporizer 13. q

Steam is introduced into the vaporizer 13 under: the packing 20, andpreferably through a perforated pipe 261located near the bottom of thevaporizer and Well beneath the surface of the liquid here collected.

Residual liquid is withdrawn from the bottom of the vaporizer throughthe pipe 22, and at arate controlled by the valve 23 actuated by thefloat 25 and mechanism 24 as indicated in the drawing.

introduction of the steam, flow upwardly throughthe packing zones 20 and21, where they mingle with the other vapors formed in and entering thevaporizer. The combined vapors pass through the conduit 12 to thefractionator for fractionation. The packing zones in the vaporizer alsofunction in the fractionatingprocess in some measure in a manner similarto that of the packed sections of the fractionator proper.

The fractionated products and water are. removed either as vapors or asliquids from selected sections of the fractionator. If re.- .moved asvapors, condensers and coolersmay be provided, and if removed as liquidsit is desirable to provide coolers. It is preferable to removetheproducts as liquids-since small piping may be used, and allcondensing may bedone in the condenser 4. It is preferable to althoughif desired only a portion of the vapors may be condensed while theremainperform all the condensing in said condenser,

der is withdrawn. It is also preferable to remove the water as liquidwater since in operating in this manner impurities and malodoroussubstances dissolved in the water are removed from the system.

Two important results are accomplished by the use of steam indistillation. First, the distillation can be conducted at a much lowertemperature than if no steam is used, second, if the steam-distillationis conducted in such a manner that water as well as steam, is broughtinto'intimate contact with the liquids and vaof the products is usuallyimproved as a result of the dissolving and extraction of malodoroussubstances by the liquid Water. The

,hydrolytic effect of the warm liquid water tice the beneficial resultsattainable by a comr bined steam-distillation and fractionation processmore effective and eflicient than any used hitherto, and our apparatusprovides a means for the practice of our process. It may .pors withinthe distillation system, the odor' or may not beessential to our processof steam-distillation that fractionation occurs of steam into the lowerpart of the vaporizer and prefer to introduce the steam at this point,it is obvious that similar results may be obtained by introducing eithersteam or liquid water into the vaporizer at some point other than theone indicated in the description of our preferred process, or into thepipe still, for in each of these cases advantage would be taken of thepartial-pressure effect of the water vapor, and steam would be caused toascend into the fractionator. Also, less favorable results can beobtained by the introduction of steam or liquid water into thefractionator.

Our invention is applicable to the treatment of various liquids, and itmay advantageous- 1y apply to the re-running or steam distillat1o n ofgasoline, to the reduction of kerosene to a desired flash point, to thereduction'of lubricating distillates to the desired viscosity, and tothe distillation and fractionation. of petroleum oils, distillates, andproducts generally.

It is not essential to use a pipe-still, as other suitable heating meansmay be employed. A closed steam coil may also be positioned in thebottom of the vaporizer if so desired. 7

As many a parently widely different embodiments 0 our invention may bemade without departing from the spirit thereof, it is understood that wedo not limit ourselves to the embodiments described except as defined inthe claims.

We claim:

1. A method of fractionating a petroleum oil comprising introducing itinto a section of a fractionator, bringing ascending vapor column,-collecting liquidin the column sections, withdrawing a liquid productfrom any desired section, vaporizing part of the liquid residue leavingthe lower end of the column, returning resultant vapors to the lower endof the column, introducing steam into the unvaporized liquid residuefrom the vaporization to produce further vapors for introduction intothe lower end of the column, and then further heating and subjecting toflash-vaporization the final liquid residue remaining from the steamdistillation and introducing the resultant vapors into the bottom of thecolumn.

3. A 'fractionator for treating petroleum oils comprising a number ofsuperimposed sections containing packing material, a va- 1.

porizer-having a vapor outlet connected to deliver vapor to the bottomof the fractionator and a liquid exit, packing zones between said outletandexit, means for introducing steam into the bottom of the vaporizer, aheater for liquid, connected to receive liquid from the bottom of thevaporizer and to de liver heated liquid between the packing zones of thevaporizer, means forr'eturning condensed vapor at the top of thefractionator, means for permitting the descent of liquids and the ascentof vapors and for collecting liquid. in the sections, means forindependently withdrawing liquids from one or more sections, andaconduit connected to one or more sections for delivering a liquid to thesections. '2 r In testimony that we claim the foregoing, we havehereunto set out hand.

' EUGENE H. LESLIE.

EDWIN M. BAKER.

into intimate contact with descending liquid the liquid flowing from thepacking zones and introducing volatilized vapors forme thereby into thebottom of the fractionator.

2. The method of fractionating mineral oil which comprises introducingsuch oil into a fractionating column having packed sections and allowingit to flow downwardly therein in contact with ascending oil va ors,condens-' ing the vap leavin the top 0 the fractionating colufi.

and re g condensate to the

